SHORT NOTES ON LAND SNAILS 



Trapping Small Land Snails. The collection and culture of large num- 

 bers of the terrestrial snail, Cionella lubrica, were essential in the study of 

 the life cycle of the trematode, Dicrocoelium dendriticum. The usual 

 methods of collecting snails had to be supplemented by other procedures 

 because of peculiarities of habitat and distribution of this species. Our first 

 problem was to devise means of concentrating C. lubrica to reduce the labor 

 of collecting. 



Moist soil, almost constant shade, and a large quantity of dead canes 

 appeared to favor the congregation of snails in thickets. They could be 

 found readily, partly buried in soil, on dead canes, and under stones, boards, 

 and wet papers. However, we found it tedious and time-consuming to 

 collect C. lubrica in the open pasture without the use of collecting devices. 

 Because of our success in concentrating snails in shaded areas with gunny 

 sacks, we tried their use on the pasture. 



The snail trap for collecting C. lubrica consisted of a wet gunny sack, 

 folded 3 to 6 times, covered with 2 or more layers of rocks. Small rocks 

 were used for the lower layer, and this was covered with one or 2 tiers of 

 larger, flat rocks. Care was taken to see that they were not heavy enough 

 to press the entire surface of the sack against the ground. This arrange- 

 ment provided circulation of air, kept the heat of the sun from the fabric 

 and lower rock layers, and shaded the sack completely. The soil beneath 

 remained cool, and moisture was preserved for much longer periods than 

 in uncovered areas. 



Bait was unnecessary to attract C. lubrica to these traps; in fact, sub- 

 stances usually employed by collectors, such as oatmeal and bran, were 

 found to have no appreciable influence in attracting these snails. 



The traps were examined 2 to 4 times weekly. Specimens were found 

 in the traps on the undersides of the sacks and in the debris and soil under 

 them. When the humidity was high or following precipitation, specimens 

 were recovered occasionally from the tops of the sacks and the covering 

 rocks. As many as 26 specimens of C. lubrica were found in individual 

 traps at one time. Other species frequently encountered were Vallonia 

 pulchella, Zonitoides nitidus, Discus cronkhitei, Papilla muscorum, and 

 Helicodiscus parallelus. The slugs, Deroceras reticulatum and Arion cir- 

 cumscriptus, were attracted in large numbers. These collections were made 

 in the vicinity of Cazenovia, Madison County, New York. — Wendell H. 

 Krull and Cortland R. Mapes, abstracted from "Studies on the Biology 

 of Dicrocoelium dendriticum (Rudolphi, 1819) Loos, 1899 (Trematoda: 

 Dicrocoeliidae) , Including its Relation to the Intermediate Host, Cionella 

 lubrica (Miiller)." Appeared in The Cornell Veterinarian, vol. XLI, No. 4, 

 October, 1951 



Killing and Preparing Liguus. Killing Liguus by the ordinary method, 

 in boiling water, results in loss of color; the green lines become bronzy or 

 dirty gray. To preserve the natural color care must be taken that no steam 



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